Breast changes that may occur:

• Breast lump or irregularity
• Breast tenderness, swelling, or increased warmth

Changes in the shape of the nipples may include:

• Inverted nipples, in which the nipple is indented into the areola, but will often come out with breast stimulation or during pregnancy
• Retracted nipples, in which the nipple was raised above the surface but begins to pull inward and does not come out when stimulated

Nipple discharge may be:

• Milky (galactorrhea)
• Clear, bloody, or discolored (green or brown) discharge
• Present only with pressure on the breast or without pressure (called spontaneous discharge)
• Present in one or both nipples

Skin changes around the nipple may include:

• Redness, tenderness, and cracking of the skin surface of the nipple
• Dimples, puckers, or a rash on the skin of the nipple or the areola (darker skin that surrounds the nipple)

The health care provider will take your medical history and perform a physical examination.

Tests that may be done to look for causes of nipple discharge:

• Prolactin level
• Thyroid function tests
• Head CT scan or MRI to look for pituitary tumor

Other tests that may be done include:

• Mammography, performed in all cases
• Ultrasound of the breast
• Breast biopsy if a mass or lump is found, if the mammogram is abnormal, or if the discharge is occurring on its own without any pressure on the breast
• Ductography or ductogram, an x-ray with contrast dye injected into the affected milk duct
• Skin biopsy, if Paget's disease is a concern